Types of Salivary Gland Cancers
Mount Sinai treats all types of salivary gland cancer. Salivary gland cancers take on many forms:
- Mucoepidermoid carcinoma: Most mucoepidermoid carcinomas start in the parotid glands. They develop less often in the submandibular glands or in minor salivary glands inside the mouth. These cancers are usually low grade, but they can also be intermediate or high grade. Low-grade mucoepidermoid tumors have a much better prognosis than high-grade ones.
- Adenoid cystic carcinoma: Adenoid cystic carcinoma is the most common type of cancer in the minor salivary glands. It is usually slow growing and often appears to be a low-grade tumor. It is very hard to completely get rid of and often comes back after surgery, sometimes many years later. The outlook for patients with low-grade adenoid cystic carcinoma is much better than for high-grade tumors of this type.
- Adenocarcinomas: Adenocarcinoma is a term used to describe cancers that start in gland cells (cells that normally secrete a substance). There are many types of salivary gland adenocarcinomas.
- Acinic cell carcinoma: Most acinic cell carcinomas start in the parotid gland. They tend to be slow growing. They are usually low grade, but how far they have grown into nearby tissue is probably a better predictor of prognosis.
- Polymorphous low-grade adenocarcinoma: These cancers tend to start in the minor salivary glands. They are low grade and usually curable.
- Adenocarcinoma, not otherwise specified: When viewed under a microscope, these cancers have enough features to distinguish them as adenocarcinomas but not enough detail to classify them further. They are most common in the parotid glands and the minor salivary glands, and can be of any grade.
- Rare adenocarcinomas: Several types of adenocarcinoma are quite rare. Many of these tumor types tend to be low-grade and usually have a very good outcome. Examples of include:
- Basal cell adenocarcinoma
- Clear cell carcinoma
- Sebaceous adenocarcinoma
- Mucinous adenocarcinoma
Other rare adenocarcinomas are more likely to be high grade and may have a less favorable outcome. These include oncocytic carcinoma and salivary duct carcinoma.
Several other rare cancers can develop in the salivary glands, with mixed prognoses. These include:
- Squamous cell carcinoma: This cancer occurs mainly in older men. It can develop after radiation therapy for other cancers in the area. When this pathology is identified in the parotid gland, it is important to investigate whether it represents a metastasis from a skin malignancy. This type of cancer tends to have a poorer outlook.
- Epithelial-myoepithelial carcinoma: This rare tumor tends to be low grade, but it can come back after treatment or spread to other parts of the body.
- Parotid gland tumors: A number of tumors can develop in the parotid gland (a salivary gland near the ear). Some of these tumors may have spread from other parts of the body, entering the parotid gland by way of the lymphatic system. Among the tumors seen in the parotid gland are lymphoma, melanoma, and squamous cell carcinoma.
- Submandibular and parotid (salivary) gland tumors: The submandibular gland may develop recurrent infections and/or blockages, causing swelling as well as an abnormal mass contained within. This mass may need to be removed by surgically excising the entire gland.
Most masses that develop in the parotid gland are due to benign tumors, which are generally painless and move around easily when manipulated. Even if benign, these tumors should be removed, as they will not go away on their own and will continue to increase in size over time, causing facial disfigurement.
Unfortunately, some masses can be cancerous. If you have pain or facial numbness or paralysis, the likelihood of the parotid mass being cancerous increases signficantly.
Malignant mixed tumors
Malignant mixed tumors are classified as:
- Carcinoma ex pleomorphic adenoma
- Metastasizing mixed tumor
Carcinoma ex pleomorphic adenoma accounts for the vast majority of malignant mixed tumors. The other two are extremely rare.
Carcinoma ex pleomorphic adenoma develops out of a benign mixed tumor (pleomorphic adenoma). This type of tumor occurs mainly in the major salivary glands. Both the grade of the cancer and how far it has spread (stage) are important in predicting the outcome of this cancer.
Our salivary gland cancer specialists function as part of The Tisch Cancer Institute — a multi-disciplinary research and clinical care institution whose membership encompasses all Mount Sinai physicians and researchers whose work involves cancer. Call us today to make an appointment. We care, and we can make a difference.